The inventive subject matter is generally directed to rigid foam panels that are adapted to the size and shape of framed cavities in buildings such as stud cavities formed in walls, ceilings, floors, or under roof decks during building construction. More particularly, the panels have features that enable a close conforming fit to the parallel vertical studs defining the cavity, while allowing for easy insertion. For sake of illustration, the inventive subject matter will generally be described in the context of the cavity formed by studs, particularly stud cavities for vertical walls.
Dimensional lumber is lumber that is cut to standardized width and depth, specified in inches. Carpenters extensively use dimensional lumber in framing wooden buildings. Common sizes include 2×4 (also two-by-four and other variants, such as four-by-two in the Australia, New Zealand, and the UK), 2×6, and 4×4. The length of a board is usually specified separately from the width and depth. It is thus possible to find 2×4s that are four, eight, and twelve feet in length. In Canada and the United States, the standard lengths of lumber are 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24 feet (1.83, 2.44, 3.05, 3.66, 4.27, 4.88, 5.49, 6.10, 6.71 and 7.32 meters). For wall framing, “stud” or “precut” sizes are available, and are commonly used. For an eight-, nine-, or ten-foot ceiling height, studs are available in 92⅝ inches (235 cm), 104⅝ inches (266 cm), and 116⅝ inches (296 cm). The term “stud” is used inconsistently to specify length; where the exact length matters, one must specify the length explicitly.
North America softwood dimensional lumber sizesNominalActualNominalActualNominalActualin × inmm × mmin × inmm × mmin × inmm × mm1 × 2 ¾ × 1½ 19 × 38 2 × 2 1½ × 1½ 38 × 38 4 × 43½ × 3½  89 × 89 1 × 3 ¾ × 2½ 19 × 64 2 × 3 1½ × 2½ 38 × 64 4 × 63½ × 5½  89 × 1401 × 4 ¾ × 3¼19 × 89 2 × 4 1½ × 3½ 38 × 89 4 × 83½ × 7¼ 89 × 1841 × 6 ¾ × 5½ 19 × 1402 × 6 1½ × 5½ 38 × 1406 × 65½ × 5½ 140 × 1401 × 8 ¾ × 7¼19 × 1842 × 8 1½ × 7¼38 × 1848 × 87¼ × 7¼184 × 1841 × 10¾ × 9¼19 × 2352 × 101½ × 9¼38 × 2351 × 12¾ × 11¼19 × 2862 × 121½ × 11¼38 × 286(Source https://en.wikipedia.org/wiki/Lumber)
Lumber's nominal dimensions are larger than the actual standard dimensions of finished lumber.
Metal studs are available in various sized including 1⅝″, 2½″, 3½″, 3⅝″, 4″, 5½″ and 6″ widths or web depths.
Wood or steel studs may be spaced at 12″, 16″ or 24″ on-center based on wall height. For purposes of illustrating principles of the inventive subject matter, a 16″ on-center spacing will generally be used in the following discussion.
Currently, in the United States and Canada, wood or metal stud framed buildings (buildings built with wood or metal framing vertical members, usually spaced approximately 16″ on center, running from floor to ceiling), are insulated by placing fiberglass bat, cellulose, spray foam, or other type of “cavity fill” insulation between the studs in the wall. This kind of framing may also be referred to as “stick built.” With increasing environmental regulations, buildings need to be more efficient than in the past. Many of the traditional methods of insulating stick-built buildings no longer meet code for new construction. This has resulted in increases in wall thickness, addition of rigid board to the outside of the building, and the growth of the spray polyurethane insulation market. Polyurethane and polyisocyanurate foams provide approximately double the R-value per inch compared to rigid polystyrene board, fiberglass, and cellulose insulation. When properly installed at appropriate thickness, rigid closed-cell foam is also a vapor retarder and air barrier, which contributes to the efficiency of the building.
Rigid foam boards or panels have been used to fill stud cavities in masonry construction. However, such boards are purely rectangular and are difficult to place into cavities because of variability in the dimensions of the cavities resulting from the wood milling and/or construction variabilities. Such boards must be trimmed to fit into cavities onsite, if they are too large, or they may be too small, leaving significant dead space. Accordingly, conventional rigid foam boards increase construction time and costs and may not adequately insulate.
In view of the foregoing, there is a need for board or panel foam insulation systems that have high R-values and which: (1) can be easily installed in standard stud cavity spacings; (2) adjust for manufacturing and construction variability for a given spacing; and (3) that are inexpensive and easily manufactured.